Pneumatic hammer.



H. .|.I KIMMAN.

' PNEuMATlc HAMMER.

(Application led June 24, 1901. Renewed July 19, 1902.)

Patented Aug. I9, |902.

No. 797,5!5. Patented Aug.\l9, |902.

H. J. KIMMAN.

PNEUMATIC HAMMER.

(Application l'ed June 24, 1901. Renewed July 19, 1902.) (No Mudel.) 4 Sheets-Sheet 2.

No. 707,5I5. Patentad Aug. I9, |902.

H. J. KIMMAN.

PNEUMATIC HAMMER.

(Application filed June 24, 1901. Renewd July 19, 1902.) l (No Model.)

4 Sheets-Sheet 4.

lllllmlmnnr :o l Zemfefy; .ZLQ l' `tl ifrnn STATES -Afr'nNT OFFICE.

HENRY J. KIMMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CHICAGO PNEUMATIC TOOL COMPANY, OF TRENTON, NEI/V JERSEY, A CORPO- RATION OF NEW JERSEY.

PNEUMATIC HAMMER.

SPECFlGATON forming part of Letters Patent No. 707,515, dated August 19, 1902.

Application lel .Tune 24| 1901. Renewed July 19, 1902. Serial No. 116,243. (No model.)

hammer operating in a percussion manner-.

that is, a large number of strokes per minute; and the invention relates particularly to the construction and arrangement of the vcontrolling-valve mechanism,which admits and cuts oft fluid to each end of the cylinder to operateihe piston-hammer, all of which will more fully hereinafter appear.

The principal object of the invention is to provide a simple, economical, and efficient pneumatic hammer.

A further object of the invention is to provide a pneumatic hammer with simple, economical, and eiiicient controlling-valve mechanism for admitting and cutting off the motive iluid to each end of the cylinder.

Further objects of the invention will appear from an examination of the drawings and the following description and claims.

The invention consists principally in a pneumatic hammer in which' there is combined a cylinder provided with a reciprocating piston-hammer, a handle-base provided with a cylindrical projection extending into the rear end of the cylinder to close the same and provide an annular valve-chamber in connection therewith, and a tubular controlling-valve reciprocatingly mounted in such valve-chamber to govern the admission ot the motive fluid to the cylinder.

The invention consists, further and finally, in the features, combinations, and details of construction hereinafter described and claimed.

In the accompanying drawings, Figure lis a sectional elevation taken through the hammer at or near its longitudinal center, as indicated byline 4 of Fig. 7, showing the piston-hammer and controlling-valve in one position; Fig. 2, a cross-sectional View taken on line 2 of Fig. 1 looking in the direction of the arrow; Fig. 3, a detail view of the tubular controlling-valve; Fig. 4, a longitudinal sectional view of the cylinder with other parts detached, taken on line 4 of Fig. 7 looking in the direction of the arrow; Fig. 5, va similar view taken on line 5 of Fig; Fig. a cross-sectional view taken on line 6 of Figs. 4, 5, 8, and 9; Fig. 7,a cross-sectional View taken on line 7 of Figs. 4, 5, 8, and 9; Fig. 8, alongitudinal sectional View of the cylinder with other parts removed, taken on line S of Fig. 11; Fig. 9, a similar view taken on line 9 of Fig. 10; Fig. 10, across-sectional View taken on lines 10 of Figs. 4, 5, 8, and 9; Fig. 11, a cross-sectional view taken on lines 11 of Figs. 4, 5, 8, and9; Fig. 12, a cross-sectional view taken on lines 12 of Figs. 4, 5, 8, and 9. Figs.' 13, 14, 15, and 16 are cross-sectional views taken on lines 13, 14, 15, and 16, respectively, of Figs. 4, 5, 8, and 9; and Fig. 17, a longitudinal sectional detail ofthe cylinder and detached mechanisms, taken on the same line as Fig. 1, showing the controlling-valve and piston-hammer in different position from that shown in Fig. 1.

In constructing a pneumatic hammer in accordance with these improvements I make a cylinder portion a of the desired length and diameter and provide it with a long cylindrical operating-chamber b, also of the desired length and diameter. One end of this cylinder is provided with a bushing c, into which the shank d of the desired tool is litted and which closes such end'of the chamber. To transform the energy of the motive fluid intoworlr done, a piston-hammer o7,

is provided and reciprocatingly mounted in the operating-chamber of the cylinder, so that as the motive lluid enters at one endthe rear-of the cylinder the hammer is driven forward to contact the tool-shank and accomplish the necessary work, while the pressure and expansion of motive luid in the front end of the cylinder drives the piston-hammer back again to its initial position.

In order to provide for the proper supply of motive fluid to each end of the cylinder to operate the piston-hammer, a handle portion j' is provided, the base of which has a tubular projection g, entering the rear end of the cylinder to close such end of its operating-chamber. The rear end of the cylinder is formed for a short distance to a diameter slightly 'larger than that of the operating-chamber, so that when the tubular projection of the handle-base is in position it forms an annular Valve-chamber h between such tubular projection and the walls of the cylinder. In this annular valve-chamber is mounted a tubular or shell valve c', the body portion of which is of a diameter smaller than the head portion, so that it forms, as it were, a differential valve, the inner side of which-that containing the smallest area-is constantly acted upon by fluid pressure, while the other or outer end-that containing a larger superficial area-is acted on intermittently by the fluid-pressure to reciprocate such valve, as will be hereinafter' more fully described.

Describing the passages for the introduction and exhaust of motive fluid for the purpose of operating the piston hammer, the handle is provided with a main supply-channel j, adapted to be opened and closed by a throttle-valve, the operating-lever 7c of which is only shown. connects with the axial opening in the tubular projection of the handle-base,which axial opening practically forms a continuation thereof. Arranged transversely in the axial opening of the tubular projection is a partition Z and a number of by-passes m, so that as motive fluid enters from the main supplychannel it enters these by-passes around the partition and into the operating-chamber of the cylinder between the partition and the head of the piston-hammer to move such hammer forward. /Vhen the hammer has reached its forward limit of motion, as shown in Fig. 17, motive fluid passes constantly through perforations n in the tubular projection, thence through a plurality of perforations o in the controlling-valve through passages p in the cylinder, (see Figs. 4 and 17,) from which it passes forward and enters the operating-chamber of the cylinder opposite an annular groove q, formed in the hammer-head. From this annular groove it passes into passages r, (see Fig. 8,) thence back to the rear of the valve-chamber and between the head of the valve and the handle-base, Where, acting on the largest superficial area of the valve, it moves the same forward into the position shown in Fig. 17. This movement of the controlling-valve closes the bypass m and cuts off the motive fluid from entering at the rear of the piston-hammer. At

l the same time the motive fluid between the piston-hammer and the partition in the tubular projection of the hammer passes out through the exhaust-passage s, thence backwardly through such passageinto an annular This main supply channel` foams groove t in the cylinder, thence over into a second annular groove u out through the perforations fu into an annular exhaust-chamber lw, formed between the hammer-handle and the outside walls of the cylinder, from whence it is discharged through the exhaust-perforations into the open air, thus exhausting the excess of atmospheric pressure from the back of the piston-hammer. The hammer is now in position to be moved backward, and in order to accomplish this result the motive fluid passes from the annular chamber q formedv in the hammer-head, through the channels y to the front of the cylinder between the piston-hammer and the shank of the tool,and operates to move the piston-hammer forward. During the backward movement of the piston-hammer it passes the exhaust-opening s, cuts off the escape, and cornpresses the remaining air between the partition in the tubular projection and the hammer-head to absorb or take up the recoil of the hammer. During the same movement of the piston-hammer the exhaust-openings 2O at the front are uncovered, so that the excess of pressure in front of the piston-hammer and between it and the tool-shank may be exhausted into the open air. At the same time the motive fluid between the differential valve and the handle-base passes forwardly through the passage V2^ and the continuation 21 thereof, where it enters the forward part of the operating chamber and passes out through the exhaust-openings 20, thus permitting the constant supply of motive fluid that passes through the perforations nin the tubular projection and 0 in the controllingvalve to act upon the shoulder 22, by which it is in a measure confined againsta shoulder formed by the passage p to move such controlling-Valve backward and again open the by-passes m. This permits a supply of motive fluid to again enter the operating-chamber of the cylinder between the hammer-head and the partition in the tubular projection to again move such piston-hammer forward. The shoulder 22 on the valve at the same time cuts off communication between the annular channels t and u and acts to close the exhaust from the rear end of the operatingchamber.

An examination of the drawings will show that when the controlling-valve is moved forward into the position shown in Fig. 17 it is IOO IIO

desirable to have some means by which any air between the front end of such controllingvalve and the shoulder 24, formed by the cylinder-walls, may escape. To accomplish this result, supplementary exhaust-openings 23 are provided adjacent to the shoulder which forms the inner end wall ofthe annular valve-chamber, so that any air confined between such shoulder and the front end of the tubular valve will pass out through such opening. Emergency exhaustpassages 25 are also provided in the cylinder-walls, which connect with the extreme forward end of the operating-chamber, so that when the pistonhammerduring its forward motion, as shown in Fig. 17, passes the forward exhaust-openings, any air confined in the front end of the operatingchamber will pass rearwardly through these emergency exhaustpassages into the forward end of the annular valvechamber and out through the openings 23.

To secure the handle to the cylinder, the rear end of the cylinder is screw-threaded at 26 and the handle portion provided with an internal screw-threaded bore adapted to engage the same. The handle is also provided with two pairs of clamping-'lugs 27, having bolts 28 extending therefrom to clamp the same together, as shown in Fig. 2, and act to lock all the parts in the desired assembled position.

I claiml l. In a tool of the class described, the combination of a cylinder provided with a reciprocating piston-ham mer, a handle-base provided with a cylindrical projection extending into the rear end of the cylinder to close the same and provide an annular valve-chamber between it and the cylinder, and a tubular controlling-Valve reciprocatingly mounted in such valve-chamber to govern the admission of the motive iluid to the cylinder, substantially as described.

2. In a tool of the class described, the combination of a cylinder provided with a reciprocating piston-hammer, a handle-base provided with a tubular projection extending into the rear end of the cylinder to close the same and provide an annular valve-chamber between it and the cylinder, and a tubular controlling-valve reciprocatingly mounted on such projection to govern the admission oi motive iiuid, substantially as described.

3. In a tool of the class described, the combination of a cylinder provided with a reciprocating pistonhammer, a handle-base provided with a tubular projection extending into the rear end of the cylinder to close the same forming a continuation of the supplychannel and providing an annular chamber between it and the cylinder, a partition in such tubular projection providing a by-pass for admitting the motive fluid to the cylinder, and a tubular controlling-valve surrounding such projection and reciprocatingly mounted in the annular valve-chamber to admit the motive fluid to the cylinder, substantially as described.

4. In a tool of the class described, the com bination of a cylinder provided with a reciprocating piston-hammer, a handle provided with an integral tubular projection extending into the rear end of the cylinder to close the same form a continuation of the supplychannel and provide an annular valve-chamber between it and the cylinder and provided with perforations communicating with the continuous opening to furnish motive fluid for the front end of the cylinder, a transverse partition in such tubular projection :forming in connection therewith a by-pass through which the motive i'luid passes to the rear end of the cylinder, and a tubular controllingvalve surrounding such projection and reciprocatingly mounted in the valve-chamber to govern the admission'of the motive fluid to therear chamber ofthe cylinder,substantially as described.

5. In a tool of the class described, the Combination of a cylinder provided with a reciprocating hammer, a handle-base provided with a tubular projection extending into the rear end of the cylinder to close the same and provide in connection therewith an annular valve-chamber, a tubular differential controlling-valve slidingly mounted in the annular valve-chamber to govern the admission of the motive fluid to the cylinder, means for admitting a constant supply of motive Iluidto the smaller area of the tubular differential controlling-valve, and means arranged to be operated by the movements of the pistonhammer to intermittently admit motive fluid to the larger superficial area of the differential valve to reciprocate the same, substantially as described.

6. In a tool of the class described, the combination of a cylinder provided with a reciprocating piston-hammer, a handle-base provided with a tubular project-ion extending into the rear end of the cylinder to close the same and form the connection with an annular valve-chamber, a shouldered tubular differential valve in such valve-chamber, a main supply-passage formed in the hammer-handle and extending into the axial tubular opening of the projection, by-passes in such tubular projection,a transverse partition arranged in such tubular projection to assist in forming such by-passes and admit motive Huid to the rear of the piston-hammer, constant-supply passages n in the tubular projections, constant-supply passages o in the tubular valve to furnish a constant supply of motive fluid to the smaller superficial area of the shoulder, a passage r in the Walls of the cylinder connecting the operating-chamber with the valve-chamber to the rear of the face of the valve and arranged to be opened and closed by the movements of the piston-hammer to furnish an intermittent supply of motive iiuid to the larger area of the differential valve and reciprocate the same, substantially as described.

7. In a tool of the class described, the combination of a cylinder provided with a reciprocating piston-hammer, a handle-base provided with a tubular projection extending into the rear end of the cylinder to close the same and form in connection therewith an annular valve-chamber, a tubular dierential valve slidingly mounted in such valve-chamber, means for furnishing a constant supply ot' motive fluid to the smaller area of the differential valve, means arranged to be oper* ated by the movements of the piston-hammer to furnish an intermittent supply of motive ICO IIO

'luid to the larger area of the differential valve and reciprocate the same,an annular exhaustchannel u connecting With the open air, a second exhaust-channel t connected With passages through the cylinder with the rear end of the operating-chamber and arranged to be opened and closed by the movements of the reciprocating controllingwalve',substantially as described.

8. In a tool of the class described, the coinbination of a cylinder provided With a reciprocating hammer,ahand1ebase provided with a tubular projection extending into the rear end of the cylinder to close the same and form an annular valve-chamber in connection therewith, a tubular differential valve slidingly mounted in such valve-chamber, means furnishingr a constant supply of motive Huid to operat-e such differential Valve in one direction, means for furnishing an intermittent supply of motive fluid to the larger supericial area thereof to move it in the opposite direction, an exhaust-passage in the rear end of the cylinder arranged to be opened and closed by the movements of the differential valve, a supplementary valve-exhaust opening connected with the front end of the annular Valve to release any air confined therein, and an emergency exhaust-passage in the Walls of the cylinder connected with the front end of the operating-chamber and the eX- haust-openings in the annular chamber to exhaust any air in the front end of such operating-chamber, substantially as described.

9. In a tool of the class described, the combination of a cylinder provided with a reciprocating hammer and a rear outer threaded portion, a handle-base provided with a central tubular projection extending into the rear end of the cylinder to close the same and provide an annular chamber between it and the Walls of the cylinder, an outer annular tubular projection having an internal threaded bore engaging With the threads on the rear end of the cylinder, and bolt mechanisrn Jfor locking the threaded tube of the handle-base in engagement With the threaded surface of the cylinder, substantially as described.

HENRY J. KIMMAN.

Witnesses:

HARRY IRWIN CROMER, ANNIE C. COURTENAY. 

